It just occurred to me that for some reason Puppet, a character added later who isn't even from FNAF 1, got her maledom animation before Chica or Bonnie did. What the heck? Granted I'm a bit biased because Chica is my favorite, but still.
For Bonnie, perhaps if you allow her to hack your security system there will be a chance that the puzzle to stop her hack will be one with an alternate, harder solution, with the icon being a heart or something. If you figure out the alternate solution and connect the power source to the new symbol (maybe before doing the regular solution on top of it) Bonnie's hacking will backfire on her and leave her submissive to the player, who can do something with her on-stage.
Chica should be pretty easy. I just found out that if you stare at the left door when Chica is in the hall, breathing, she'll teleport back to the stage instead of going behind you. Her maledom animation could be initiated simply by having a new animation play out where if you catch her entering your office or watch the doorway when she enters she'll freeze up due to her programming telling her not to be seen, and the player gets to have their way with her. If that would be too easy catching her entering the office could instead prompt her to turn around and leave, and you can close the door on her in order to trap her like with Frederika.
On the topic of Chica, this might be too much effort for a small detail but I think it'd be cool if there were settings for Chica to possibly have clothing like her Toy version. I'm thinking her bib could either be large enough to cover her nipples or just barely cover the top of her breasts leaving her nipples exposed. As for her bottom it could either cover her whole pelvis being something like panties or booty shorts, or be a thong similar to Springtrap's strapon but pink and without the dildo. In the sex scenes the clothing could simply be laid aside somewhere depending on the animation, or maybe just her bottom if having her top on wouldn't cause any clipping.